More than half the world's working women are trapped in insecure jobs, often without protection from employment laws, according to a UN report.

Around 600 million women live in countries where domestic violence is not a crime. And just 28 countries have parliaments where at least 30% of the MPs are women, says the first report issued by the new agency, UN Women.

While 139 countries and territories now guarantee gender equality in their constitutions, the report said millions of women in many countries are still deprived of economic resources and access to public services and all too often "are denied control over their bodies, denied a voice in decision-making and denied protection from violence."

"For most of the world's women the laws that exist on paper do not always translate into equality and justice," it said. "In many contexts, in rich and poor countries alike, the infrastructure of justice - the police, the courts and the judiciary - is failing women, which manifests itself in poor services and hostile attitudes from the very people whose duty it is to fulfil women's rights."

In the 169-page report, UN Women called on governments to repeal laws that discriminate against women, provide more funding to support innovative services such as legal aid and specialized courts to ensure that women can access the justice system and make certain that there are female police, judges and legislators.

While women have achieved greater economic empowerment through laws that prohibit discriminatory practices, guarantee equal pay and provide for maternity and paternity leave, the report said 53% of working women - 600 million in total - are in vulnerable jobs such as self-employment, domestic work, or unpaid work for family businesses which often lack the protection of employment laws.

It said women are still paid up to 30% less than men in some of the 117 countries that have laws guaranteeing equal pay in the workplace.

UN Women stressed that laws must be enforced if women are to achieve equality, but pointed to many barriers.

"In the developing world, more than one third of women are married before the age of 18, missing out on education and exposed to the risks of early pregnancy," the report said.

Domestic violence is now outlawed in 125 countries but 603 million women live in countries where it is not a crime - and even where there are laws, the report said, "millions of women report experiencing violence in their lifetimes, usually at the hands of an intimate partner."